Is Your Furnace Drying Out Your Skin?

Many homeowners think that a gas furnace dries out their home’s air, leading to dry, itchy skin.

And that’s why they have to leave lotion and lip balm within arms reach 24/7.

But is the furnace really the mastermind behind your home’s dry air?

No way; that’s a myth. The gas furnace itself does not dry out your air.

We’ll explain why the furnace is (mostly) innocent, what IS causing your air to dry out—and what you can do about it.

Why furnaces don’t ‘dry out’ air

‘Dry air’ is air with low water vapor content.

Furnaces do not lower the amount of water vapor in the air; they merely increase the temperature of the air.

In fact, heating the air actually increases the total amount of water vapor that the air can hold (called ‘absolute humidity’). But it does not add to or take away any water vapor from the air.

Think of heating air like pouring a 1 liter of water from a small bottle to a larger bottle. The larger bottle can hold more water, but the amount of water does not change.

OK, so if the furnace isn’t to blame for dry air, then what is?

Where does dry air comes from?

Cold air is dry air. So if your air is dry, that’s because the furnace is pulling in cold air from the outdoors or an unconditioned space.

What could cause your furnace to pull in cold air? A common culprit is leaky air ducts in unconditioned spaces, like your attic.

Leaks on the return ducts (the side that’s pulling air from your home into the furnace) will suck in air from the unconditioned space as well. So, while your furnace may be a patsy (it’s circulating dry air from the attic), it’s not the core cause.

One solution to dry air: duct sealing

Dry air can infiltrate your home in various ways, but sealing air duct leaks gives you the biggest bang for your buck keep keeping dry air out.

Leaky ductwork is a common problem, too. According to ENERGY STAR, for a typical home “about 20 to 30 percent of the air that moves through the duct system is lost due to leaks, holes, and poorly connected ducts.”